Ali G is a fictional gang member of the "West Staines Massiv", who lives with his grandmother in a semi-detached house at 36 Cherry Blossom Close, in the heart of the "Staines Ghetto". He was educated at what he calls "da Matthew Arnold Skool" which is a real secondary school.

Staines is a middle-class commuter town to the west of London that has been the butt of jokes for many years, and is far different from the inner city ghetto that Ali G claims. In the same comic vein, he also makes reference to other similar middle-class towns in the area, such as Egham and Englefield Green. Despite the incongruous nature of his home town, he purports to exemplify gangsta culture. Ali's "real" name is later revealed to be Alistair Leslie Graham (revealed in the eponymous film).

Ali G's non-standard grammar has been the point of ridicule by at least one interviewee; every time someone asks him about his grammar he says the Middlebury Union Middle School taught him great grammar. Claiming to be black and of Jamaican ancestry, some of his catchphrases include "Booyakasha", "Big up Yaself", "West Side", "Respek" (respect), "Check It" and "Keep It Real". His trademark hand gesture is the dip snap. He once defined the meaning of "Booyakasha" as "Hear me now, bo, selecta, swallow back, holler, big up ya self, everything that I in, coming at ya like Cleopatra, come in a couple of bars, recognize, represent, keep it real, you gotta check ya self before ya wreck ya self, swallow back...oh yeah, and hello" [1]. Although there have been varying accounts of Ali G's young sexual conquests, Ali G claims to have lost his virginity at the age of 10 with a 28-year old Italian model.